AP Environmental Science Chapter 3 Vocab

Population

Population

group of same species in the same place

Adaptation

characteristic that helps organism survive and reproduce

Natural Selection

survival of the fittest, how evolution works

Selective Pressures

reason for organisms with certain characteristics to have either a survival benefit or disadvantage

Artificial Selection

humans choose which organisms to breed

Biodiversity

variety of life/species in an area

Speciation

formation of new species

Allopatric Speciation

a physical barrier separates a species into two isolated groups. They eventually evolve into different species

Endemic

native to a specific place

Background Extinction Rate

number of species expected to go extinct over a period of time, without human impacts

Evolution

change in a population over time

Genetic Diversity

differences in genes within a population

Natural Disruptions

Periodic (regular intervals, like hurricane season), Episodic (irregular and occasional, like El Niño), Random

Bottleneck Effect

a sudden event destroys most of a population, the genetics of the survivors are very different from the original pop.

Ecosystem

organisms and the physical environment with which they interact

Community

all of the living organisms in an area

Biosphere

everywhere living things live on Earth

Generalist Species

able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources

Specialist Species

animals that require very unique resources. Need a limited diet or specific habitat conditions to survive.

Population Distribution / Density

number of organisms in an area.

Exponential Growth

unrestricted growth, occurs when there are no limiting factors on a population

Linear Growth

growth at a constant rate

Logistic Growth

growth slows as a population experiences limiting factors and reaches a carrying capacity

Limiting Factors (Density-dependent and independent)

slows/stops a pop. from growing. Density-dependent is affected by pop. size.

Carrying Capacity

maximum healthy population that can fit in an area

Survivorship Curves

Type I (high survival in early life, decline later), Type II (constant mortality), Type III (high death rate in early life)

Biotic Potential

number of offspring a population can produce under ideal conditions with no limiting factors (exp. growth)

K-selected Species

few offspring, high parental care, long lives, large animals, thrive in stable environment (K=carrying capacity)

R-selected Species

many offspring, low parental care, short lives, small organisms, thrive in unstable environment (r=reproduce)

Island Biogeography Theory

higher number of species will be found in large areas closer to the mainland

Ecotourism

tourism directed toward exotic/threatened environments, intended to support conservation efforts and observe wildlife.